A drum type washing machine has an outer tub, simply referred to as “a tub” hereinafter, in which a cylindrical basket drum is mounted to rotate about a horizontal or inclined axis. With the laundry loaded inside, the drum is rotated in the tub containing water. The drum thus rotating makes the laundry tumble, whereby the stain or the like is removed from the laundry. Well known conventional drum type washing machines have a substantially rectangular parallel-piped housing equipped with a front door that opens laterally to put clothes in. When the door is opened, a throw-in opening provided at an end of the drum becomes visible through an opening provided in the tub.
About the above drum type washing machine, many consumers are dissatisfied because of the difficulty in loading or unloading clothes. In drum type washing machines with the above structure, the throw-in opening is located very low. With this design, the difficulty in loading or unloading clothes cannot be completely eliminated even by placing the washing machine on a dedicated platform. Considering the above complaint, some drum type washing machines have a drum with an inclined axis to make the throw-in opening directed obliquely upward. In other washing machines, the throw-in opening is designed larger. These structures, however, cannot yield a satisfactory result for those who are accustomed to the user-friendly whirl type washing machines. Another problem is related to the following washing method often carried out by consumers: (1) put the laundry in a solution of bleach or the like stored in a bucket or the like, and (2) transfer the laundry with the solution of bleach, or only the laundry, to the washing tub of the washing machine. With the conventional drum type washing machine, the laundry often drips the liquid onto the floor when only the laundry is transferred from the bucket to the washing tub. Furthermore, it is very difficult to transfer the liquid itself from the bucket to the washing tub.
One possible method for eliminating the above user-unfriendly drum type washing machine is to form the throw-in opening not in the front but in the top of the housing, as in the case of whirl type washing machines. To form the throw-in opening in the top of the housing, however, it is necessary to form openings also in the tub placed right under the throw-in opening and in the drum enclosed in the tub. Such a structure causes various problems that do not occur in conventional whirl type washing machines or drum type washing machines. Examples of the problems are as follows:    (1) To load or unload the laundry into and out of the drum, it is necessary to open at least two doors: a tub door provided in the peripheral wall of the tub, and a drum door provided in the peripheral wall of the drum. For user-friendliness, it is desirable to design these doors easy to operate.    (2) To avoid damaging clothes in the course of opening or closing the door, it is desirable, for example, to prevent the laundry from getting caught by the door.    (3) The drum is not usually large enough to form a large opening in its peripheral wall. Despite such a constraint, the loading or unloading of the laundry should be as easy as possible.    (4) Measures should be taken to prevent the laundry from falling into the space between the tub and the drum.